Integral multichannel separator

ABSTRACT

An integral multichannel separator for separating and removing foreign particles from engine inlet air is disclosed. The multichannel separator utilizes a plurality of concentric rings mounted in the air inlet passageway to divide the passageway into multiple flow paths. Each ring has a particle entrapping portion at the trailing edge. Each particle entrapping portion of the rings is connected with scavenge struts which support the rings as well as transport the particles for disposal. Deflector rings cooperate to prevent particle rebound into the main airstream.

Unite States atent ll I'll" I /f I I IF- Rygg 1 Dec. 18, 1973 INTEGRALMULTHCHANNEL SEPARATOR 3,673,77l 7/1972 Dickey 55/306 [75] Inventor:Gregers G. Rygg, Oxford, Conn. Primary Examiner Bemard Nozick [73]Assignee: Avco Corporation, Stratford, Conn. AttorneyCharles M. Hogan etal.

22 Pl d: A 30, 1972 l 1 57 ABSTRACT [21] Appl 234;! An integralmultichannel separator for separating and removing foreign particlesfrom engine inlet air is dis- [52] US. Cl. 55/306, 55/440, 60/39.()9 P,closed. The multichannel separator utilizes a plurality 244/53 B 417/12]of concentric rings mounted in the air inlet passage- [511 im. c1 Bold45/08 y to divide the passageway into multiple flow p [58] Field ofSearch 55/306, 307, 440; E g has a p i mr pping portion at the trail-60/39 09 P; 244/53 B; 417/121 G ing edge. Each particle entrappingportion of the rings is connected with scavenge struts which support the[56] Referenc Cit d rings as well as transport the particles fordisposal. De-

UNITED STATES PATENTS flector rings cooperate to prevent particlerebound 2,931,460 4/1960 McEachern 55/306 mm the a'rstream 3,148,0439/1964 Richardson et al 55/306 7 Claims, 3 Drawing Figures INTEGRALMULTICI-IANNEL SEPARATOR BACKGROUND OF THE INVENTION This inventionrelates to air intakes, particularly intakes for gas turbine engineswhich are required to operate in sand or dust laden air, and moreparticularly to an integral multichannel separator incorporated in theair intake passageway.

The use of turbine-powered helicopters in severe sand laden atmosphericconditions has resulted in a dramatic increase in cases of engineerosion damage and has underscored the need for effective systems toprotect gas turbine engines from sand and dust ingestion. Solutions tothese problems have yielded a wide variety of particle separatorconcepts which are generally appended to the engine installation.Examples of such separators are shown in U. S. Pat. Nos. 3,371,471 and3,534,548, both issued to H. D. Connors, and U. S. Pat. No. 3,521,431issued to H. D. Connors and F. D. Buckley, all of which are assigned toAvco Corporation.

The increased engine protection afforded by these units has more thanjustified their use. However, physical limitations imposed by thisadd-on approach sometimes result in the aircraft system suffering fromlower sand collection efficiencies, higher weight, and larger losses inpower than may be necessary. These problems can be significantly reducedby providing a particle separator which is incorporated within theengine air inlet. An example of such a separator is U. S. Pat. No.3,673,71 l issued to T. A. Dickey and assigned to Avco Corporation. Useof swirl and deswirl vanes such as in the Dickey patent, in someinstances, may not be desirable.

Accordingly, it is an object of this invention to provide an improvedparticle separator which is integral with the engine air inletpassageway and which does not impart swirl and deswirl to the airflow inthe particle separator stage.

A further object of this invention is to provide a particle separatorhaving high scavenge efficiency due to inertia separation.

A still further object of this invention is to provide a particleseparator having multichannel separating facilities and which furtheroperates as an FOD screen.

Another object of this invention is to provide a particle separatorwhich exploits inlet housing curvature to provide effective particleseparation.

Yet another object of this invention is to provide a particle separatorwhich lends itself to installation within existing engine intakepassageway structures.

SUMMARY OF THE INVENTION This invention provides an improved integralmultichannel separator for removing foreign particles from the stream ofair supplied to the compressor of an engine. The separator consists ofstatic components which are mounted in the annular air intakepassageway. A plurality of concentric rings is mounted in the passagewayby hollow scavenge struts. The trailing edge of each ring includes aparticle catching portion displaced axially one to the other to minimizepressure loss due to the drag of the catching portion. The catchingportion of each ring is supported by and is in communication with thehollow struts. A sawtooth shape of the catching portion allows capturedparticles to flow therealong into the hollow struts. Concentricdeflector rings are associated with each concentric ring to preventparticle rebound into the main airstream.

Other details, uses, and advantages of this invention will becomeapparent as the following description of the exemplary embodimentthereof presented in the accompanying drawings proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show apresent exemplary embodiment of this invention in which:

FIG. 1 is a side view, partially cut away, through part of the airintake of a gas turbine engine which is provided with the multichannelparticle separator according to the present invention;

FIG. 2 is a sectional view (not to scale) taken along line 22 of FIG. 1downstream of the separator and looking upstream; and

FIG. 3 is a sectional view taken along line 33 of FIG. 2 particularlyshowing the sawtooth shape of the catching lips.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT Reference is now made to FIG.1 which illustrates one exemplary embodiment of the improved particleseparator of this invention which is designated generally by thereference numeral 110. The separator 10 is mounted at the forward end ofthe turbine engine just ahead of the compressor stage 12. The annulargear housing 14 forms the inner wall of the engine air inlet passageway16. The outer wall of the passageway 16 is defined by the annular inlethousing 18.

The particle separator 10 is mounted downstream of the entrance of theair inlet passageway 16 and before the first compressor stage 12 definedby the axial compressor casing 20. The separator 10 comprises aplurality of annular concentric cylinders or rings 22, 24 and 26 mountedin the air passageway 16. The rings 22, 24 and 26 provide splitter wallsto define a plurality of smaller annular passageways in passageway 16.The concentric ring 26 forms the inner wall of a manifold chamber 28 forwhich wall 30 defines the outer dimension of the manifold 28.

Each concentric ring 22, 24 and 26 is supported and secured, by anysuitable means, in the passageway 16 by hollow struts 311. The struts 31are mounted in radial fashion about the passageway 16. The outer end ofeach strut 31 is connected to and in communication with the manifoldchamber 28. Each concentric ring 22, 24 and 26 is formed with a particlecatching portion or lip 32, 34 and 36, respectively, at the respectivetrailing edge thereof. The catching lips 32 and 34 are in opencommunication with the adjacent hollow struts 31. It should be notedthat the catching lip 36 is a flange member separated from theconcentric ring 26 but may be considered as a cooperating element of theconcentric ring 26. The area defined by the catching lip 36 and theconcentric ring 26 is in direct communication with the manifold chamber28. Accordingly, it is seen that any particles which are captured by thecatching lips 32, 34 and 36 will be transmitted to the manifold chamber28 either through the hollow strut 31 in the case of lips 32 and 34 ordirectly to the chamber 28 in the case of lip 36.

In order to enhance the transmission of entrapped particles from thecatching lips to the hollow strut 31 or chamber 28, the catching lips32, 34 and 36 are formed in a chevron or sawtooth pattern betweensupporting struts, as seen in FIG. 3. For illustrative purposes in FIG.3, concentric ring 22 and catching lip 32 has been unfolded in a linearfashion. In the drawings, clean air is represented by long arrows andthe dust or foreign particles are diagrammatically represented by dotsand dashes. The sawtooth pattern of the catching lips between thesupporting struts allows the captured particles to flow along respectivecatching lip and into the scavenge strut. It is further seen that of allthe particles trapped between two supporting struts, one half of theparticles will flow to one strut and the remainder will flow to theother strut. Any suitable means such as a blower or the like (not shown)may be used to transmit the particles from the hollow struts 31 to themanifold chamber 28 from whence they are exhausted overboard throughsuitable means such as ejector tubes or the like 38 which are mounted onwall 30 in open communication with chamber 28.

in order to minimize the particle rebound effects, i.e., particlesstriking the concentric ring and rebounding into the main airstream,concentric deflector cylinders or rings 42, 44 and 46 are mounted in thepassageway 16 in close proximation to the respective concentric ring.The deflector rings 42, 44 and 46 are supported in passageway 16 by thestruts 31. The deflector rings are positioned radially inward from eachrespective concentric ring in such a way that particles rebounding fromthe respective concentric rings will engage the respective deflectorring thereby being prevented from returning to the main stream, suchparticles, because of their inertia, will be carried into the catchinglip portion. Aslight air gap exists between the downstream end of eachdeflector ring and the upstream edge of each catching lip such that aportion of the air passing between respective concentric ring anddeflector ring will be able to return to the main airstream.

Referring once again to FIG. I, it is seen that the catching lipportions 32, 34 and 36 of each respective concentric ring 22, 24 and 26are displaced axially downstream one to the other to minimize blockageeffects and pressure loss to drag on the catching lips.

in operation, the particle laden air enters the passageway l6 andtravels in an axial direction. The particles are carried by theirinertia to the catching lip portion as the airstream is acceleratedthrough the curvature of the passageway 16. A portion of the air passingbetween the concentric ring and deflector ring will be able to return tothe main airstream through the slots just upstream of the upstream edgeof the catching lips while the sand, because of its inertia, will becarried into the catching lip. It may be further seen that the separatorwill serve as an FOD screen for preventing ingestion of large objectsthrough the passageway to the compressor stage 12.

Because of the unique structural features of the particle separator ofthis invention, it is seen that there is no need for extraneous add-onstructures to be placed on the engine. The particle separator is mountedin the air inlet passageway upstream of the first compressor stage.Accordingly, it can be seen that this invention accomplishes theobjectives hereinabove set forth.

While a present exemplary embodiment of this invention has beenillustrated and described, it will be recognized that this invention maybe otherwise variously embodied and practiced by those skilled in theart.

What is claimed is:

1. In a gas turbine engine the combination comprising:

an air intake passageway;

a plurality of concentric separating elements mounted in said passagewayand dividing said passageway into plural flow paths, said elementshaving a particle entrapping portion at the trailing edge thereof;

a plurality of concentric deflector rings of like number as saidseparating elements mounted in said passageway, a deflector ring beingmounted in close proximation to a separating element and positionedradially inward therefrom wherein particles rebounding from saidseparating elements will be prevented from returning to the passagewaywhereby such particles will be carried into the particle entrappingportion due to particle inertia; and

a row of spaced radially extending hollow struts mounted in saidpassageway, said row of struts supporting said concentric separatingelements and said deflector rings, said struts having openingstherealong wherein said hollow interior of each strut is incommunication with the particle entrapping portion for receivingparticles entrapped thereby.

2. The combination according to claim 1 in which the outermostconcentric separating element defines the inner wall of a manifoldchamber;

an outer wall cooperating with said outermost separating element todefine the manifold chamber, said manifold chamber being incommunication with said hollow struts for receiving particles therefrom.

3. The combination according to claim 2 in which said particleentrapping portion of the outermost separating element is separatedtherefrom wherein direct communication is provided between saidoutermost separating element and said manifoldchamber.

4. The combination as set forth in claim 1 in which said concentricseparating elements comprise concentric rings and in which theentrapping portion of each separating ring is a catching lip.

5. The combination as set forth in claim 4 in which the downstream edgeof each deflector ring terminates upstream of the leading edge of therespective catching lip wherein a slight air gap exists therebetweenwhereby air passing between the respective concentric ring and deflectorwill be able to return to the passageway.

6. The combination according to claim 4 in which said catching lipextending between any pair of hollow struts is formed in a sawtoothshape whereby particles entrapped thereby will flow therealong to one orthe other of said hollow struts.

7. A multichannel separator in an inlet of a gas turbine enginecomprising:

a plurality of concentric rings mounted in the inlet passageway, each ofsaid rings terminating, said rings defining a plurality of passagewayswithin the inlet passageway;

a catching lip at the downstream end of each concentric ring andcooperating therewith to catch particles within the passageway;

a concentric deflector ring mounted in said inlet passageway in closeproximity with each concentric ring, each deflector ring beingpositioned radially inward from -each respectively concentric ring;

lips wherein said catching lips are in communication with the interiorof said hollow struts whereby particles entrapped by each catching lipare transmitted to the interior of said hollow strut.

1. In a gas turbine engine the combination comprising: an air intakepassageway; a plurality of concentric separating elements mounted insaid passageway and dividing said passageway into plural flow paths,said elements having a particle entrapping portion at the trailing edgethereof; a plurality of concentric deflector rings of like number assaid separating elements mounted in said passageway, a deflector ringbeing mounted in close proximation to a separating element andpositioned radially inward therefrom wherein particles rebounding fromsaid separating elements will be prevented from returning to thepassageway whereby such particles will be carried into the particleentrapping portion due to particle inertia; and a row of spaced radiallyextending hollow struts mounted in said passageway, said Row of strutssupporting said concentric separating elements and said deflector rings,said struts having openings therealong wherein said hollow interior ofeach strut is in communication with the particle entrapping portion forreceiving particles entrapped thereby.
 2. The combination according toclaim 1 in which the outermost concentric separating element defines theinner wall of a manifold chamber; an outer wall cooperating with saidoutermost separating element to define the manifold chamber, saidmanifold chamber being in communication with said hollow struts forreceiving particles therefrom.
 3. The combination according to claim 2in which said particle entrapping portion of the outermost separatingelement is separated therefrom wherein direct communication is providedbetween said outermost separating element and said manifold chamber. 4.The combination as set forth in claim 1 in which said concentricseparating elements comprise concentric rings and in which theentrapping portion of each separating ring is a catching lip.
 5. Thecombination as set forth in claim 4 in which the downstream edge of eachdeflector ring terminates upstream of the leading edge of the respectivecatching lip wherein a slight air gap exists therebetween whereby airpassing between the respective concentric ring and deflector will beable to return to the passageway.
 6. The combination according to claim4 in which said catching lip extending between any pair of hollow strutsis formed in a sawtooth shape whereby particles entrapped thereby willflow therealong to one or the other of said hollow struts.
 7. Amultichannel separator in an inlet of a gas turbine engine comprising: aplurality of concentric rings mounted in the inlet passageway, each ofsaid rings terminating, said rings defining a plurality of passagewayswithin the inlet passageway; a catching lip at the downstream end ofeach concentric ring and cooperating therewith to catch particles withinthe passageway; a concentric deflector ring mounted in said inletpassageway in close proximity with each concentric ring, each deflectorring being positioned radially inward from each respectively concentricring; a plurality of radially extending hollow struts mounted in saidinlet passageway, said struts supporting each concentric ring andcatching lip and deflector ring, said strut having openings therealongin communication with each of said catching lips wherein said catchinglips are in communication with the interior of said hollow strutswhereby particles entrapped by each catching lip are transmitted to theinterior of said hollow strut.